The present invention relates to a device and a method for bonding friction material of clutch pulley, and more particularly, to a device and a method for bonding friction material of clutch pulley, which can simplify bonding processes by bonding friction material to a clutch pulley of an electromagnetic clutch for a compressor with a liquid phase adhesive, and which can improve productivity and prevent bonding error of the friction material by automatically inspecting a coated condition of the liquid phase adhesive.
A compressor of an air conditioning device for an automobile is operated by controllably receiving driving power of an engine through an electromagnetic clutch.
The electromagnetic clutch includes a field core assembly supported on a compressor housing, and a hub and disc assembly including a disc absorbed to or separated from the friction surface of a clutch pulley according to a an action of the field core assembly and a hub connected to a driving shaft of the compressor.
The friction surface of the clutch pulley has a number of banana slots to induce a flow of flux by the field core assembly, so that the disc is absorbed onto the friction surface of the clutch pulley.
Meanwhile, an edge region of the friction surface of the clutch pulley has a friction material inserting groove of a round form for bonding the friction material, so that rotary power of the clutch pulley is transferred to the disc by the friction force during absorption of the disc.
As well known, there is a method for bonding friction material to the clutch pulley. The bonding method includes the steps of: inserting a bonding sheet, which is made in such manner that nonwoven fabric is coated with epoxy resin, into the friction material inserting groove; attaching the ring-type friction material onto the bonding sheet; and bonding the friction material to the clutch pulley by high frequency induction hardening of epoxy resin.
In the above method, the bonding sheet being in a rolled state is unrolled to be provided. At this time, to minimize a waste amount of the bonding sheet, the bonding sheet is divided into three pieces at an angle of 120 degrees according to shapes of the ring-type friction material, and then arranged in the ring type, and inserted into the friction material inserting groove.
According to the above typical method, because an adhesive of an expensive sheet type is used and the bonding sheet is stamped in the form of an arch, non-stamped regions are all wasted, and it requires lots of material costs.
Furthermore, the typical method has several disadvantages in that it is difficult to divide the thin and light bonding sheet into several pieces of sheets by blanking, and complicated equipments cause higher error rate and deterioration of productivity.
If the bonding sheet stamped in the form of the arch is applied to other clutch pulley having a friction material inserting groove of different size, also molds or equipments of different type must be used, and so interchangeability of the equipments is lowered.
Furthermore, the typical method has bad influences on working environments as lots of dust is generated when epoxy resin of a solid phase coated on the nonwoven fabric is stamped.
Moreover, during absorbing the pieces of sheets by a transferring device in a vacuum condition and inserting the pieces of sheet into the friction material inserting groove, the bonding sheet is folded, missed or overlapped.
The nonwoven fabric of a rough surface prevents a smooth vacuum absorption of the pieces of sheet, and so, the pieces of sheets frequently drop down. Furthermore, there occurs an insertion error, such as deviation of the pieces of sheets from the correct position as they are not correctly inserted into the friction material inserting groove.
The insertion error causes a bonding error of the friction material, and thereby, durability of the clutch pulley is deteriorated. Because the friction material is arranged on the pieces of the bonding sheets after the pieces of the bonding sheets are inserted into the friction material inserting groove, only the bottom of the friction material is bonded to the clutch pulley. As the result, durability of the friction material is considerably lowered.
To solve the above problems, Korean Patent Publication discloses a method and a device for bonding friction material of clutch pulley.
In the prior art, the clutch pulley is moved by a transferring unit, which moves intermittently.
A valve, which has a nozzle such as a needle, is mounted at a predetermined position where the clutch pulley is stopped. The valve coats the friction material inserting groove with liquid phase adhesive of thermohardening while moving in a circumferential direction along the friction material inserting groove of the clutch pulley.
Meanwhile, in a state that the valve is fixed, the liquid phase adhesive can be coated from the valve to the friction material inserting groove during rotation of the clutch pulley.
The nozzle of the valve directs both side edges of the friction material inserting groove.
The clutch pulley coated with the liquid phase adhesive is transferred by the transferring unit to perform the next process, and then the friction material is inserted into the friction material inserting groove.
After that, in a state that the liquid phase adhesive is adhered on the bottom and both sides of the friction material, the liquid phase adhesive is hardened through a heating process and cooled to complete the bonding processes of the friction material.
However, the liquid phase adhesive of high viscosity requires a high-pressure pumping device to provide the liquid phase adhesive to the valve.
The limitation of the pumping device frequently incurs that the friction material inserting groove is coated with the liquid phase adhesive unevenly, and so there occurs the bonding error during insertion of the friction material into the friction material inserting groove.
To solve the above problem, it would be considered that inspectors manually check the coated condition of the liquid phase adhesive. However, in fact, it is difficult that the inspectors checks the coated condition of products one by one during a production line, and difficult to perform an exact inspection. After all, the typical method has a restriction in fundamentally preventing the bonding error.
Additionally, because the manual inspection takes lots of inspection period of time, the typical method lowers productivity of the products and increases the manufacturing cost due to a demand of manpower.
Korean Patent Publication No. 1999-34484 by the same inventor as the present invention discloses a method for bonding friction material using liquid phase adhesive. However, Korean Patent Publication No. 1999-34484 also has the same problems as the prior arts, and described only a preparing method without detail description of a friction device.
Therefore, the inventor of the present invention have repeatedly studied about device and method for effectively bonding friction material of a clutch pulley, and as the result, the present invention has been proposed.
Accordingly, the present invention is directed to a device and a method for bonding friction material of clutch pulley that substantially obviates one or more problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a device and a method for bonding friction material of clutch pulley, which can improve productivity and prevent bonding error of the friction material by automatically inspecting a coated condition of the liquid phase adhesive coated on a friction material inserting groove during a bonding process of friction material of the clutch pulley.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the device for bonding friction material of a clutch pulley includes: a transferring part for intermittently transferring a clutch pulley having a friction material inserting groove of a round shape, wherein friction material of a ring type is inserted into an end thereof; a dispenser unit having a nozzle for injecting a liquid phase adhesive to the friction material inserting groove of the clutch pulley; a vision inspector for sensing a coated condition of the liquid phase adhesive by the dispenser unit and for generating warning sound when the coated condition of the liquid phase adhesive is bad, the friction material inserting groove of the clutch pulley being coated with the liquid phase adhesive; a friction material inserting part for inserting the friction material into the friction material inserting groove of the clutch pulley coated with the liquid phase adhesive; and an induction heating part for inducting-heating and hardening the liquid phase adhesive while compressing the friction material so as to bond the friction material to the friction material inserting groove.
The vision inspector includes: a vision camera for sensing the coated condition of the liquid phase adhesive; a control unit for receiving sensing signal of the vision camera and comparing and determining the sensing signal with a set value; and a buzzer for generating warning sound according to output signal of the control unit when the control unit determines a coating error.
the vision inspector further includes a warning light lighted by output signal of the control unit when the control unit determines the coating error.
In another aspect of the present invention, the method for bonding friction material of clutch pulley includes the steps of: (S100) intermittently transferring a clutch pulley by a transferring part, the clutch pulley having a friction material inserting groove of a round shape wherein friction material is inserted into an end thereof; (S110) injecting and coating a liquid phase adhesive by a dispenser unit having a nozzle capable of injecting the liquid phase adhesive into the friction material inserting groove of the clutch pulley; (S120) sensing the coated condition of the liquid phase adhesive coating the friction material inserting groove of the clutch pulley and generating warning sound if the coated condition of the liquid phase adhesive is bad; (S150) inserting the friction material into the friction material inserting groove of the clutch pulley coated with the liquid phase adhesive by a friction material inserting part; and (S160) induction-heating and hardening the liquid phase adhesive by an induction heating part while compressing the friction material to bond the friction material to the friction material inserting groove.
In the coated condition inspecting step (S120), the friction material bonding method further includes a step (S130) of lighting a warning light at the same time when a vision inspector generates warning sound if the coated condition is bad.
The friction material bonding method further includes a step (S140) of manually correcting a bad coated region of the liquid phase adhesive coating the clutch pulley by a worker using a syringe for providing the liquid phase adhesive, when the worker recognizes the warning outputted from the vision inspector.
It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.